Figure 6.

Intracranial light delivery decreased yohimbine-induced reinstatement but not pellet-priming-induced reinstatement of food seeking in eNpHR3.0 but not eYFP rats. A, Pellet priming- and yohimbine-induced reinstatement: mean ± SEM active lever presses in the first 30 min of a regular extinction session in which water injections were given before the session and the first 30 min of a test session in which either four noncontingent pellets were delivered at the beginning of the session or yohimbine injections (2 mg/kg, i.p) were given before testing. Data are shown for the control (intraperitoneal water injection) and the test sessions (pellet or yohimbine) with and without light delivery; n = 14 eYFP and n = 15 eNpHR3.0. *Different from the no-light (off) condition, p < 0.01. B, Phenotype of yohimbine-induced Fos neurons in dorsal mPFC: representative immunohistochemical staining of Fos⁺ and CaMKII⁺ (left) and Fos⁺ and GAD⁺ neurons (right). Scale bars, 20 μm.